Which comes first?

I would say the track plan, including bridges, gorges, mountains, etc.. Then lay the track and set buildings. Lastly scenic the layout. Kinda the opposite of real life where the scenery is already there.

It depends on the situation.  But in most cases, it's usually best to lay the track work first, get it running good, then set your buildings later.

I think it's best to consider a conceptual track plan in conjunction with the scenery and terrain that you want on the layout - hills, valleys, rivers, towns, bridges, tunnels and yards as well as any structures that you must have - including stations, control towers, water tanks, etc. I suggest that you begin by sketching these features and an approximate track plan on a piece of paper. Then refine your concept. When you have a clear idea of how the layout might look, you can better define the exact track plan and track pieces required either by making an accurate drawing on paper or on computer software.

MELGAR

All good responses.

I'll add that it depends A LOT on what kind of "buildings" you wish to use.

If you are planning on having a bunch of post-war style operating accessories (or modern equivalents), you may want to dedicate a section of your layout to having an organized area (or multiple areas) for them.  (Maybe that is not your goal since this is in the "Scenery and Structures" forum, but if it is, it's something to consider heavily)

The answer is very different if you just mean small track side structures like small stations, switch towers, etc.  Those can in a fair number of cases (assuming you don't have a bunch of minimum clearance concentric loops with no "land" to speak of in between them) be figured out later.

It's hard to "accidentally" have enough room for a 342/345 culvert operating pair, or a 456 coal ramp, 364 lumber loader, 164 log loader (particularly to incorporate both loading and unloading), modern rotary coal tipple, etc.  Some (like the Tipple) you really need to plan a lot for them to fit.

Also, do you mean actual towns with full blocks worth of buildings?  That requires a lot of thought (and dedicated space) to plan as well.  Some structures/accessories also have larger footprints than you instinctively would think.  Strong examples are some of the nice MTH operating accessories (gas station, fire house, car wash, transfer dock).  All of these take up a huge amount of space.

-Dave

I think the chicken came first.

OK, here's a dumb question,,,,,,,,,,how would one "lay track" with buildings and such all over the place????

@Hot Water posted:

OK, here's a dumb question,,,,,,,,,,how would one "lay track" with buildings and such all over the place????

Like in reality. Building in the proposed right of way. Buy the building and land, and move the building. Lay the track.

Or in the opposite case. Is the rail line running across valuable property? Reroute the rail or remove it altogether. Put up your building.

Always remember: You own the railroad and the terrain.

But to Hot Water's comment, it does seem to create excessive and needless labor it place scenery and then decide the rail right of way. Nothing done cannot be altered. Just plan ahead as best you can to minimize alterations.